Protein and carbohydrates in detoxification processes of a generalist herbivore

Herbivorous insects possess a variety of physiological mechanisms for tolerating toxic plant compound. Of these, detoxification by cytochrome P450 enzymes is generally considered to be the most important. The inducibility of cytochrome P450 monooxygenases and other xenobiotic-metabolizing enzymes is thought to reflect material and energy costs of biosynthesis. In this study we investigated the effect of protein-carbohydrate balance on detoxifications processes in a generalist herbivore, Melanoplus differentialis. First we performed a choice-experiment to examine whether the addition of gramine (an alkaloid present in grasses) to diets that varied in their protein: carbohydrate ratios affected nutrient regulation behavior. In a second experiment we constrained grasshoppers to a range of diets with and without gramine that varied in their protein:carbohydrate ratio. We recorded consumption, mass gain and microsomal proteins.